A transmission apparatus for transmitting client data over a transmission network has been known. An example of such a transmission apparatus is an ADM (Add-Drop Multiplexer) apparatus for transmitting SONET/SDH (Synchronous Optical Network/Synchronous Digital Hierarchy) frames or OTN (Optical Transport Network) frames. The transmission apparatus has an internal clock and generates timings of various processing periods for signal processing such as frame periods based on an internal clock.
As a related technology, an apparatus for accommodating and multiplexing a client signal has been known which accommodates or multiplexes a client signal in an OTN frame, and separates the accommodated or multiplexed signal from the received OTM frame and outputs it as the client signal. The client signal accommodation and multiplexing apparatus includes an accommodating means for applying overhead to the client signal of 1.238 Gbit/s or less and accommodating the client signal into a digital frame through mapping. The client signal accommodation and multiplexing apparatus includes an arranging means for arranging a plurality of TSs (Tributary Slots) of 1.238 Gbit/s or less in an ODU0 (L) (Lower order ODU (Optical Channel Data Unit) 0) frame. The client signal accommodation and multiplexing apparatus includes a multiplexing means for accommodating or multiplexing the digital frame in or on the TS of the ODU0(L) frame through mapping.
Related art is disclosed in Japanese National Publication of International Patent Application No. 2011-176750.